Young black gay and bisexual men are sixteen times more likely to contract HIV than are young white men who have sex with men, despite the fact that they exhibit safer sex practices, a new study shows.

"Our study illuminates how HIV disparities emerge from complex social and sexual networks and inequalities in access to medical care for those who are HIV-positive," said senior study author Brian Mustanski, PhD, who serves as director of the Northwestern Institute for Sexual and Gender Minority Health and Wellbeing at Northwestern University's Feinberg School of Medicine, in a statement.

"Their social and sexual networks are more dense and interconnected, which from an infectious disease standpoint makes infections transmitted more efficiently through the group," Mustanski continued. "That, coupled with the higher HIV prevalence in the population, means any sexual act has a higher chance of HIV transmission."

The disparity is particularly noteworthy and alarming considering the young black men who have sex with men who took part in the study reported lower rates of sexual risk behaviors, fewer sexual partners, and more lifetime HIV tests than their young counterparts. The study was conducted by analyzing data from more than 1,000 gay men, aged 16 to 29, in Chicago, and was published in the Journal of Acquired Immune Deficiency Syndromes.

"Overall, young black MSM do not report higher rates of HIV risk behaviors like condomless sex," study coauthor Ethan Morgan, PhD, said in a statement. "But aspects of their social networks align with increased HIV risk. By learning more about young black MSM's social networks, we can better understand what drives such persistent racial disparities in HIV—and close that gap."

These results follow similar conclusions found in previous studies, and with the CDC's warning in 2016 that if current HIV rates persist, half of black men who have sex with men would contract HIV at some point in their lives, as well as one in four Latino men who have sex with men facing the same fate.

Last year, a new study from the CDC found that while overall HIV infections had dropped, they were still on the rise among young men who have sex with men.